diff --git a/renderer.lua b/renderer.lua
index cd21d7d..55ab68c 100644
--- a/renderer.lua
+++ b/renderer.lua
@@ -107,4 +107,55 @@ function M.tool_call_end(content, is_error)
     end
 end
 
+-- Phase 3: Norris autonomous mode frames. Banner-style on enter/exit,
+-- step counter per iteration, red HALT banner when the destructive-op
+-- gate fires. The interactive prompt also gets a ⚡ marker when Norris
+-- is active (handled in repl.lua's prompt() function per PHASE0.md §9).
+-- See docs/PHASE3.md §3 renderer row.
+
+function M.norris_begin(goal)
+    emit(A.bold, A.cyan, "─── NORRIS MODE ─────────────────────────",
+         A.reset, "\n")
+    if goal and goal ~= "" then
+        emit(A.dim, "  goal: ", A.reset, goal, "\n")
+    end
+    emit(A.bold, A.cyan, "─────────────────────────────────────────",
+         A.reset, "\n")
+end
+
+function M.norris_step(n, max_n, descr)
+    emit(A.dim, ("  ─ step %d/%d ─ "):format(n, max_n), A.reset)
+    if descr and descr ~= "" then emit(A.dim, descr, A.reset) end
+    emit("\n")
+end
+
+function M.norris_halt(step_n, max_n, reason, action)
+    emit(A.bold, A.red, "─── NORRIS HALT ──────────────────────────",
+         A.reset, "\n")
+    emit(A.dim, "  step:   ", A.reset, ("%d/%d"):format(step_n, max_n), "\n")
+    emit(A.dim, "  reason: ", A.reset, A.red, tostring(reason), A.reset, "\n")
+    -- action may be a long string (command line or JSON-serialized tool call);
+    -- truncate at 400 chars to keep the banner readable
+    local act = tostring(action or ""):gsub("\n", " ")
+    if #act > 400 then act = act:sub(1, 397) .. "..." end
+    emit(A.dim, "  action: ", A.reset, act, "\n")
+    emit(A.bold, A.red, "──────────────────────────────────────────",
+         A.reset, "\n")
+end
+
+-- Norris loop exit. status ∈ {"done", "aborted", "budget_exhausted",
+--                              "stalled", "broker_error"}.
+function M.norris_end(status, reason)
+    local color = (status == "done") and A.cyan or A.red
+    local label = status:upper():gsub("_", " ")
+    emit(A.bold, color, "─── NORRIS ", label, " ──",
+         (" "):rep(math.max(0, 28 - #label)),
+         A.reset, "\n")
+    if reason and reason ~= "" then
+        emit(A.dim, "  ", reason, A.reset, "\n")
+    end
+    emit(A.bold, color, "──────────────────────────────────────────",
+         A.reset, "\n")
+end
+
 return M